Control device

ABSTRACT

It is possible to provide a small-size and light-weight control device having a structure which prevents detaching of a board even when an external shock is applied without using a screwed connection. The control device is formed by a case including at least one board, a radiator, and a protection cover. The case includes at least one latch portion in an upper part or a lower part of a board support frame.

This application is a division of application Ser. No. 12/444,503 filedApr. 6, 2009, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a control device for operating anindustrial appliance.

BACKGROUND ART

Two types of control devices have been proposed. In a first example,components are fixed with screws (see, for example, Patent Document 1).In a second example, components are mounted from one direction withoutusing screws (see, for example, Patent Document 2).

Referring to FIG. 11, the first existing example is described. As shownin FIG. 11, a control device is constructed by placing a printed circuitboard 102 on a base 103, screwing a screw 119 into a through hole 113 inthe printed circuit board 102 and a screw hole 106 in a board mountingboss 107 so as to fasten the printed circuit board 102 to the base 103,joining a fitting protrusion in an inner cover mounting boss 109 of thebase 103 to a fitting recess in a boss 116 on an inner cover 104,pinching the printed circuit board 102 with the inner cover 104,fastening the inner cover 104 with screws 120, and covering the entirebase 103 with a cover 105.

Referring to FIGS. 12 and 13, the second existing example is described.As shown in FIG. 12, an existing control device is assembled as follows.First, an LCD case 210 is fixed to a back surface or another part of aprinted circuit board 202 with connecting pieces 211 c by soldering orthe like. Next, as indicated by arrow A in FIG. 13, a side plate 213 ofan LCD cover 212 is hooked to bent portions 211 b of a side plate 211 ofthe LCD case 210, an LCD cover 212 is rotated around the hooked portionas indicated by arrow B in the figure, and notches 213 a in another sideplate 213 of the LCD cover 212 are engaged with other bent portions 211a. By moving the LCD cover 212 in this state, the bent portions 211 aand the notches 213 a are engaged with each other, and the LCD case 210is engaged with the LCD cover 212, whereby assembly is completed.

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2001-244648 (p. 3, FIG. 1)

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. 63-000198 (p. 2, FIGS. 1 and 2)

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

Control devices are broadly used in the fields of robots, machine tools,automobiles, and the like. High reliability and ease of maintenance arerequired for a control device, while reduction in size and weight isalso desired. Thus, by changing the mounting structure of a controldevice from a two-dimensional structure to a three-dimensionalstructure, the space for disposing the control device is efficientlyused. However, in the mounting structure of a board, electroniccomponents are densely mounted on the board, the areas to which stackedboards are attached are limited, and it has been desired that a controldevice be configured such that the boards are not separated even when anexternal shock is applied.

However, because an existing control device is configured such thatstacked boards are fastened with screws, it is necessary to secure aspace and an insulation distance for fastening the screws, therebycausing a problem in that reduction in size is hindered. Moreover, thereis a problem with fastening using screws in that the screws may beloosened by repeated vibrations or shocks and the boards may fall off.Furthermore, there is a problem in that workability is reduced becauseit is necessary to remove the screws in order to carry out maintenanceof the boards.

In addition, in the case of a top mounting method in an existing controldevice, there is a problem in that the number of parts increases becauseparts are used among the components. When the number of parts increases,reduction in size and weight becomes unfeasible, which causes a problemin that the control device has to be disposed in a larger space.

The present invention, which has been achieved to overcome the problems,aims to provide a control device having a structure with which thenumber of parts is reduced, reduction in the size and weight of thecontrol device is realized, and boards are prevented from falling offwhen an external shock is applied without using a screw connection.

Means for Solving the Problems

In order to solve the above-described problems, the present invention isconfigured as follows.

In the invention according to a first aspect, a control device comprisesa case, the case including at least one board and a radiator, whereinthe case includes at least one latch portion in an upper part or a lowerpart of a board support frame.

In the invention according to a second aspect, the case includes pillarsdisposed in four corners and the board support frame connecting thepillars.

In the invention according to a third aspect, the case includes boardsupport frames, a pair of opposing board support frames including latchportions for fixing a first board, and another pair of opposing boardsupport frames including latch portions for supporting a second board.

In the invention according to a fourth aspect, the first board isengaged with the latch portions included in the upper parts of the boardsupport frames and the second board is engaged with the latch portionsincluded in the lower parts of the board support frames.

In the invention according to a fifth aspect, the case includes boardsupport frames, a pair of opposing board support frames including latchportions for fixing a first board in upper parts thereof and elasticholes for supporting a second board in lower parts thereof.

In the invention according to a sixth aspect, at least one guide notchportion for positioning the board with respect to the case is formed inan outer peripheral surface of the board.

In the invention according to a seventh aspect, a latch portion forpositioning the radiator with respect to the case is formed in an outerperipheral surface of the radiator.

In the invention according to an eighth aspect, the radiator includes aboard including a cooling fan.

In the invention according to a ninth aspect, the control device furthercomprises a protective cover, wherein at least one recess is formed inan outer peripheral surface of the protective cover and engaged with thelatch portion of the case.

In the invention according to a tenth aspect, a control device comprisesa case including at least one board and a radiator, wherein the caseincludes at least two latch portions with different heights in an upperpart or a lower part of a board support frame.

In the invention according to an eleventh aspect, at least one pillar isincluded on a side of the latch portion.

In the invention according to a twelfth aspect, the case includes boardsupport frames, a pair of opposing board support frames including latchportions for fixing at least one of the boards, and another pair ofopposing board support frames including latch portions for fixing theboard stacked on the at least one of the boards.

In the inventions according to a thirteenth aspect and a fourteenthaspect, the board disposed on the top includes a rib being in contactwith a pillar included in the case.

In the inventions according to a fifteenth aspect and a sixteenthaspect, the latch portion engaged with an elastic hole included in thecase also serves as a pillar for supporting the board.

ADVANTAGES

With the inventions according to the first to sixteenth aspects, becausethe boards are fixed without using fastening members such as screws, thenumber of parts can be reduced and the boards are prevented from fallingoff even when an external shock is applied. Moreover, because the boardsare configured to be supported with the latch portions and the elasticholes, assembling and disassembling can be carried out easily, wherebyworkability in maintenance is improved. Moreover, because the boards canbe assembled and removed from above or below the case, workability isimproved without increasing the number of parts. Furthermore, becausethe plurality of boards can be supported by providing the plurality oflatch portions of different heights, expandability is high and space canbe efficiently used.

In particular, with the inventions according to the eleventh aspect andthe thirteenth to sixteenth aspects, the boards are prevented fromfalling off with external shocks or vibrations, because the pillars andthe ribs for fixing the boards are formed so as to hold the boards moresecurely.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of a control device according toa first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the control device accordingto the first embodiment of the present invention.

FIG. 3 is an assembled perspective view of the control device accordingto the first embodiment of the present invention.

FIG. 4 is an exploded perspective view of a control device according toa second embodiment of the present invention.

FIG. 5 is an assembled perspective view of the control device accordingto the second embodiment of the present invention.

FIG. 6 is an assembled perspective view of a control device according toa third embodiment of the present invention.

FIG. 7 is a sectional view of a control device according to a fourthembodiment of the present invention.

FIG. 8 is an enlarged view of the control device according to the fourthembodiment of the present invention.

FIG. 9 is an assembled perspective view of a control device according toa fifth embodiment of the present invention.

FIG. 10 is an enlarged view of a rib of the control device according tothe fifth embodiment of the present invention.

FIG. 11 is an exploded perspective view of a first existing controldevice.

FIG. 12 is an exploded perspective view of a second existing controldevice.

FIG. 13 is a side view of a second existing control device.

REFERENCE NUMERALS

1 case

2 first printed circuit board

3 second printed circuit board

4 protective cover

5 radiator

6 heat conductive sheet

7 first latch portion

8 second latch portion

9 guide notch portion

10 guide notch portion

11 third latch portion

12 recess

13 elastic hole

14 latch portion

15 pillar/board positioning portion

16 board support frame

17 cooling fan plate

20 latch portion

21 case

22 first latch portion

23 second latch portion

24 third latch portion

25 fourth latch portion

26 first printed circuit board

27 second printed circuit board

28 third printed circuit board

29 fourth printed circuit board

30 guide notch portion

31 guide notch portion

32 guide notch portion

33 guide notch portion

34 first pillar

35 second pillar

36 board support frame

41 rib

102 printed circuit board

103 base

104 inner cover

105 cover

106 screw hole

107 board mounting boss

109 inner cover mounting boss

113 through hole

116 boss

119 screw

120 screw

202 printed circuit board

210 LCD case

211 side plate

211 a bent portion

211 b bent portion

211 c connecting piece

212 LCD cover

213 side plate

213 a notch

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention are described withreference to the drawings.

First Embodiment

FIG. 1 is an exploded view showing a structure of a control device forcarrying out a method of the present invention. The figure shows a case1, a first printed circuit board 2, a second printed circuit board 3, aprotective cover 4, and a radiator 5.

The present invention is different from Patent Document 1 and PatentDocument 2 in that the case includes latch portions for fixing theboards to be stacked, the latch portions being disposed in an upper partor a lower part of board support frames of the case.

The case 1 includes pillar/board positioning portions 15 in the fourcorners thereof, each of the pillar/board positioning portions 15 beingconnected with board support frames 16 by adhesion or the like.Alternatively, the pillar/board positioning portions 15 and the boardsupport frames 16 are integrally formed. Elastic holes 13 are formed inlower parts of a pair of board support frames 16, and third latchportions 11 are formed in upper parts of the pair of board supportframes 16. First latch portions 7 and second latch portions 8 are formedin upper parts and lower parts of another pair of board support frames16.

Next, the first printed circuit board 2 is described. Guide notchportions 9 are formed in an outer peripheral surface of the firstprinted circuit board 2 so that the first printed circuit board 2 ispositioned with respect to the case 1.

The second printed circuit board 3 is described. Guide notch portions 10are formed in an outer peripheral surface of the second printed circuitboard 3 so that the second printed circuit board 3 is positioned withrespect to the case 1.

The radiator 5 is described. Latch portions 14 are formed on a pair ofsides of an outer peripheral surface of the radiator 5 so as to beengaged with the elastic holes 13 of the case 1.

Next, referring to FIGS. 1, 2, and 3, an assembly process of the controldevice is described. First, the second printed circuit board 3 isinserted into the case 1 such that the guide notch portions 10 formed infour positions in the outer peripheral surface are positioned along thesecond latch portions 8 formed in the case 1, and the second printedcircuit board 3 is fixed with the second latch portions 8 of the case 1.

Next, the first printed circuit board 2 is inserted into the case 1 suchthat the guide notch portions 9 formed in four positions in the outerperipheral surface are positioned along the first latch portions 7formed in the case 1, and the first printed circuit board 2 is fixedwith the first latch portions 7 of the case 1.

Next, the radiator 5 is fixed by engaging the latch portions 14 formedon the outer peripheral surface with the elastic holes 13 of the case 1.

Next, regarding the protective cover 4, recesses 12 formed in its outerperipheral surface are fixed with the third latch portions of the case1.

Second Embodiment

Next, referring to FIGS. 4 and 5, a second embodiment of the presentinvention is described. The present invention is different from thefirst embodiment in that a plurality of latch portions are formed in anupper part and a lower part of the board support frames of the case sothat three or more printed circuit boards can be fixed.

Differences from the first embodiment are described. In a case 21, firstlatch portions 22 and second latch portions 23 are formed in upper partsand lower parts of a pair of board support frames 36. Third latchportions 24 and fourth latch portions 25 are formed in upper parts andlower parts of another pair of board support frames 36. Moreover, firstpillars 34 and second pillars 35 are formed adjacent to the third latchportions 24 and the fourth latch portions 25.

Next, referring to FIGS. 4 and 5, an assembly process is described.First, a second printed circuit board 27 is inserted into the case 21such that guide notch portions 31 formed in four positions in the outerperipheral surface are positioned along the second latch portions 23formed in the case 21, and the second printed circuit board 27 is fixedwith the second latch portions 23 of the case 21.

Next, a first printed circuit board 26 is inserted into the case 21 suchthat guide notch portions 30 formed in four positions in the outerperipheral surface are positioned along the first latch portions 22formed in the case 21, and the first printed circuit board 26 is fixedwith the first latch portions 22 of the case 21.

Next, a fourth printed circuit board 29 is inserted into the case 21such that guide notch portions 33 formed in four positions in the outerperipheral surface are positioned along the fourth latch portions 25formed in the case 21, and the fourth printed circuit board 29 is fixedwith the fourth latch portions 25 of the case 21. At this time, thefourth printed circuit board 29 is fixed while being supported by thesecond pillar 35.

Next, a third printed circuit board 28 is inserted into the case 21 suchthat guide notch portions 32 formed in four positions in the outerperipheral surface are positioned along the third latch portions 24formed in the case 21, and the third printed circuit board 28 is fixedwith the third latch portions 24 of the case 21. At this time, the thirdprinted circuit board 28 is fixed while being supported by the firstpillars 34.

In the embodiment described here, latch portions of different heightsare disposed in pairs on board support frames. However, latch portionsof different heights may be disposed on the same board support frame.Needless to say, that latch portions of different heights may bedisposed, for example, on a pair of opposing board support frames. Theembodiment is described using an example having four printed circuitboards. However, needless to say, four or more printed circuit boardscan be stacked by forming latch portions of different heights. Not onlyprinted circuit boards, but also a combination of radiators andprotective covers can be stacked.

Third Embodiment

Next, referring to FIG. 6, a third embodiment of the present inventionis described. The third embodiment is different from the firstembodiment and the second embodiment of the present invention in thatelastic holes are formed in a pair of upper parts of an outer peripheralsurface of a case so as to fix a cooling fan plate.

As shown in FIG. 6, a cooling fan plate 17 has latch portions 20 formedin a pair of sides of an outer peripheral surface thereof, and thecooling fan plate 17 is disposed such that the latch portions 20 arefixed to elastic holes 13 formed in a pair of upper parts of an outerperipheral surface of a case 1.

Fourth Embodiment

Next, referring to FIGS. 7 and 8, a fourth embodiment of the presentinvention is described. The fourth embodiment is different from thefirst to third embodiments of the present invention in that latchportions of a radiator fixed to elastic holes formed in a pair of lowerparts of an outer peripheral surface of a case also serve as pillars forsupporting a board positioned above.

FIG. 7 shows a sectional view of a control device, and FIG. 8 shows anenlarged view of a latch portion. Latch portions 8 formed in a radiator5 are fit into elastic holes 13 of a case 1, and the radiator 5 is fixedto the case 1. At this time, the latch portions 8 are disposed so thatthe latch portions 8 support the bottom surface of the second printedcircuit board 3 and fix the second printed circuit board 3.

Although the latch portions are formed in the radiator and fitted intothe elastic holes in the case so that the printed circuit board issupported from the bottom, it is not necessary that the latch portionsbe formed in the radiator. The latch portions may be formed in acomponent attached to the case, such as a printed circuit board or aprotective cover. Moreover, although the radiator including the latchportions is disposed at the lowermost position in the configurationdescribed here, it is not necessary that the latch portions be disposedat the lowermost position. It is evident that a board including thelatch portions may be a board in the middle of the stack.

Fifth Embodiment

Next, referring to FIGS. 9 and 10, a fifth embodiment of the presentinvention is described. The fifth embodiment is different from the firstto fourth embodiments of the present invention in that ribs are formedon a cover in contact with the pillar/board positioning portions in thefour corners of the case.

FIG. 9 shows a perspective view of the control device, and FIG. 10 showsan enlarged view of a rib portion. Ribs 41 are formed on a protectivecover 4, and a surface of the each rib 41 is disposed in contact with acorresponding pillar/board positioning portion 15 in a case 1. By doingso, falling off is prevented due to a supporting effect of the ribs 41.

INDUSTRIAL APPLICABILITY

The present invention is also applicable to a multi-axis control device,because the number of stacks can be increased by increasing the numberof latch portions and pillars on the board support frames.

1. A control device comprising a case, the case including at least oneboard and a radiator, wherein the case includes at least two latchportions with different heights in an upper part or a lower part of aboard support frame.
 2. The control device according to claim 1, whereinat least one pillar is included on a side of the latch portion.
 3. Thecontrol device according to claim 1, wherein the case includes boardsupport frames, a pair of opposing board support frames including latchportions for fixing at least one of the boards, and another pair ofopposing board support frames including latch portions for fixing theboard stacked on the at least one of the boards.
 4. A control devicecomprising a case, the case including at least one board and a radiator,wherein the case includes at least one latch portion in an upper part ora lower part of a board support frame, and wherein the board disposed onthe top includes a rib being in contact with a pillar included in thecase.
 5. The control device according to claim 1, wherein the boarddisposed on the top includes a rib being in contact with a pillarincluded in the case.
 6. A control device comprising a case, the caseincluding at least one board and a radiator, wherein the case includesat least one latch portion in an upper part or a lower part of a boardsupport frame, and wherein the latch portion engaged with an elastichole included in the case also serves as a pillar for supporting theboard.
 7. The control device according to claim 1, wherein the latchportion engaged with an elastic hole included in the case also serves asa pillar for supporting the board.